Support proper tooltips on undo redo buttons

css/app.css

@@ -349,3 +349,45 @@ div.typeahead a.active {
     -webkit-tap-highlight-color:rgba(0,0,0,0);
     -webkit-touch-callout:none;
 }
+
+.tooltip {
+  position: absolute;
+  z-index: 1030;
+  display: block;
+  padding: 5px;
+  font-size: 11px;
+  opacity: 0;
+  filter: alpha(opacity=0);
+  visibility: visible;
+}
+
+.tooltip.in {
+  opacity: 0.8;
+  filter: alpha(opacity=80);
+}
+
+.tooltip-inner {
+  max-width: 200px;
+  padding: 3px 8px;
+  color: #ffffff;
+  text-align: center;
+  text-decoration: none;
+  background-color: #000000;
+  -webkit-border-radius: 4px;
+     -moz-border-radius: 4px;
+          border-radius: 4px;
+}
+.tooltip-arrow {
+  position: absolute;
+  width: 0;
+  height: 0;
+  border-color: transparent;
+  border-style: solid;
+}
+.tooltip.bottom .tooltip-arrow {
+  top: 0;
+  left: 50%;
+  margin-left: -5px;
+  border-bottom-color: #000000;
+  border-width: 0 5px 5px;
+}